Device for purifying liquids

ABSTRACT

A device for cleaning liquids, in particular edible oils, by means of a filter in a filter housing, the filter being connected downstream of a pump, and a motor for driving the pump, which has a rotor having a rotor disc with vanes in an immersion housing being provided in a housing, the housing, immersion housing and filter housing together forming a unit which can be at least partially introduced into the liquid which is to be cleaned and removed therefrom.

[0001] The invention relates to a device for cleaning liquids, inparticular edible oils, by means of a filter in a filter housing, thefilter being connected downstream of a pump, and a motor for driving thepump, which has a rotor having a rotor disc with vanes in an immersionhousing being provided in a housing, the housing, immersion housing andfilter housing together forming a unit which can be at least partiallyintroduced into the liquid which is to be cleaned and removed therefrom.

[0002] In both the domestic and the industrial sector, there arenumerous liquids which have to be cleaned. These include, for example,coolant or lubricant baths in machine tools, and edible oils, forexample from fryers. These are only a few examples, but the invention isintended to apply to all possible liquids which are to be cleaned.

[0003] In general, the liquid is from time to time removed from astorage tank and passed to a device for cleaning this liquid. Fromthere, the liquid is then returned to the storage tank. Often, however,only the surface of the liquid is sucked up, so that the light, floatingsubstances are removed. The heavier particles of impurities are thenremoved at the bottom from time to time after they have settled.

[0004] The present invention relates in particular to oils originatingfrom fryers. It is usual for these oils also to be sucked up, filteredand pumped back into the fryer. In this case, a cleaning powder, forexample kieselguhr, is also scattered into the medium prior tofiltration.

[0005] The cleaning of oils and fats is important because in theory,given complete cleaning, the oils and fats can be constantly reused.Given a price of approximately DM 2.00 per liter of frying oil and areduction in service life by five to ten times, a filtration system canpay for itself within a few months.

[0006] Devices of the type described above are known, for example, fromU.S. Pat. No. 3,356,218, U.S. Pat. No. 3,447,685 and in particular fromU.S. Pat. No. 3,415,181. In these devices, the oil which is to becleaned is sucked off the bottom by means of a pump and is laterallydischarged from the pump into a riser. Downstream of this riser there isa filter, through which the liquid which is to be cleaned passes beforethen being returned to the bath via a return line.

[0007] The present invention is based on the object of providing adevice which allows the liquid to be cleaned significantly more easily,more quickly and possibly without the addition of cleaning powder.

[0008] This object is achieved through the fact that the vanes arepositioned on the rotor disc and apertures for liquid which is to becleaned to pass through to reach a filter are provided in the rotordisc.

[0009] The major advantage of the present invention resides in the factthat it is now no longer necessary for the oil to be sucked out and fedto the filter, but rather the cleaning of the liquid takes place in theliquid bath itself. In this case, it is possible to use a significantlysimpler device which makes do with only a small number of components. Itis therefore also significantly less expensive and easier to handle. Theoverall result is a handheld appliance which can readily be used both inthe domestic sector and in particular also in the catering industry.

[0010] In a preferred exemplary embodiment, the overall device comprisesthree housings which hold the main functional parts. These housings arecoupled to one another in such a way that they can also quickly bedisconnected from one another, so that cleaning is facilitated. For thispurpose, the housings are connected to one another by means of quick-fitclamping elements, for example by means of quick-acting nuts. Thehousings may also at least in part be pushed into one another.

[0011] All the electronics and the drive for the pump are to beaccommodated in one housing, i.e. this housing holds the motor, theelectronics and suitable actuating components. This housing does notneed to be immersed in the liquid, for which reason it is preferablyfitted on top of an immersion housing. By contrast, the immersionhousing is introduced into the liquid.

[0012] This immersion housing holds a rotor, which is used to suck upthe liquid and convey it onward to the filter housing. The rotor isconnected, via a suitable rod, to the above-mentioned motor in thehousing which has been fitted on top. Furthermore, vanes, which may beof any desired shape and configuration, are fitted to a rotor disk ofthe rotor. All that is important is for these vanes to suck up liquidand force it onward into a shaft leading to the filter housing.

[0013] The rotor disk, together with a partition in the immersionhousing and a ring which engages around the rotor disk, forms an almostclosed housing, except for apertures in the rotor disk. The liquid issucked through these apertures into the space and conveyed through anoutlet into the above-mentioned shaft.

[0014] In another exemplary embodiment, the rotor of the pump rotates inapertures in a laminated stack. This laminated stack comprises aplurality of laminations layered on top of one another with differentapertures, the diameter of the apertures increasing from an inlet towardan outlet to the shaft. The capacity of the pump is controlled in thisway.

[0015] From the shaft, the liquid then passes into the filter housing,with the filter housing first of all having an antechamber in which anyheavy particles can settle. This antechamber is followed by the firstfilter, which is preferably a metal nonwoven. This metal nonwoven isused to separate particles out of the liquid.

[0016] The metal nonwoven is surrounded by a cage, from which the liquidif required can pass to a second filter. This filter is designed in sucha way that it removes flavors and odors from the liquid. By way ofexample, this second filter may be granules or powder in a bag. Thissecond filter is not absolutely imperative, if, for example, thecleaning powder has already been scattered into the liquid. Depending onthe particular requirements, it is also possible to provide furtherfilter stages.

[0017] In another exemplary embodiment of the invention, the filterhousing is guided on rails running along the immersion housing. Thefilter housing in this case comprises a shell part and a cover, the twobeing connected to one another by means of a hinge. After the cover hasbeen opened, a folded filter, of which the filter surface area issignificantly increased, can be inserted into the shell part.

[0018] The equipment is extremely simple to handle. The equipment isplaced into the frying basket of the fryer. The filtration cycle isstarted by pressing a button. The cycle time is approximately 5 minutes.After the filtration has ended, the equipment is put into a drip-drybasin. Of course, it is possible for the filtration cycle to beinterrupted at any time by actuation of a stop button.

[0019] Further advantages, features and details of the invention willemerge from the following description of preferred exemplary embodimentsand with reference to the drawing, in which:

[0020]FIG. 1 shows a side view of a device for cleaning liquidsaccording to the invention;

[0021]FIG. 2 shows a longitudinal section through the device shown inFIG. 1;

[0022]FIG. 3 shows a view of the device shown in FIG. 1 from below;

[0023]FIGS. 4 and 5 show a plan view of two exemplary embodiments ofrotor disks with vanes fitted to them;

[0024]FIG. 6 shows a longitudinal section through a further exemplaryembodiment of the device shown in FIG. 1.

[0025] In accordance with FIGS. 1 and 2, a device for cleaning liquidsaccording to the invention includes an immersion housing 1, to the sideof which a filter housing 2 is connected. Furthermore, a further housing3 is fitted onto the immersion housing 1 and has on it a handle 4, bymeans of which the entire device R can be carried.

[0026] A cutout 5 in the immersion housing 1 reveals quick-acting nuts 6and 7, by means of which the housing 3 and the filter housing 2,respectively, can be connected to the immersion housing 1.

[0027] In the housing 3, as shown in FIG. 2, there is a motor 8, whichis controlled by electronics 9. There are suitable operating buttons 10for actuation purposes.

[0028] Via a rod 11 which extends through the immersion housing 1, themotor 8 drives a rotor 12, which substantially comprises a rotor disk 13with vanes 14 fitted to it. The rotor disk 13 is provided below apartition 15, the rod 11 extending through this partition. The partition15, a ring 16 and the rotor 12 form a space 17 into which, when therotor 12 rotates, liquid can be sucked through apertures 18 in the rotordisk 13.

[0029] This liquid is then forced through an outlet 19 into a shaft 20which is still inside the immersion housing 1. From the shaft 20, theliquid passes through a window 21 into the filter housing 2.

[0030] In the filter housing 2, there is an antechamber 22, which isseparated from a first filter 25 by a partition 23 with openings 24.This filter is preferably a metal filter, for example a stainless-steelnonwoven. This first filter is held by a cage 26 which in turn isprovided with openings 27. Beneath the cage 26 there is a second filter28, which is preferably a filter bag containing a cleaning powder.

[0031]FIGS. 4 and 5 show two different variants of vanes 14.1 and 14.2.The vanes 14.1 are straight, while the vanes 14.2 are Archimedean.

[0032] The present invention operates in the following way:

[0033] In the assembled state shown in FIG. 1, the device R according tothe invention is picked up by the handle 4 and introduced into a liquidwhich is to be cleaned. In the process, the immersion housing 1 and thefilter housing 2 are at least partially immersed in the liquid which isto be cleaned.

[0034] Then, the motor 8 is started up by means of the operating button10 and drives the rotor 12 via the rod 11. The rotor 12 uses its rotorvanes 14 to suck liquid through the apertures 18 into the space 17, asindicated by the corresponding arrows. Furthermore, it forces the liquidthrough the outlet 19 into the shaft 20, from where the liquid passesinto the antechamber 22 of the filter housing 2. From here, the liquidis forced through the first filter 25, which above all filters particlesout of the liquid. These particles can, for example, be collected in acollecting trough 29 formed in the lower region of the antechamber 22.

[0035] From the first filter 25, the liquid passes through the openings27 to the second filter 28, which is intended in particular to filterodors and flavors out of the liquid. Then, the cleaned liquid isreturned to the liquid bath.

[0036] After it has been used, the device R can be cleaned in a verysimple way. By releasing the quick-acting nuts 6 and 7, it is possibleto detach the filter housing 2 and the housing 3 from the immersionhousing 1. In particular, it is now easy to clean the filter housing 2,it being possible for the filter 28 to be removed from its space. Ifappropriate, the cage 26 may also be designed to be removable.

[0037] In a further exemplary embodiment of the invention as shown inFIG. 6, the rotor 12 rotates within a laminated stack 30 which isarranged beneath the partition 15. This laminated stack 30 comprisesthree laminations 31.1 to 31.3 which have different apertures 32.1 to32.2. The aperture 32.1 is approximately circular in design and has thesmallest diameter. The aperture in the lamination 31.2 is likewisecircular, but has a larger diameter than the aperture 32.1. The aperture32.3 in the lamination 31.3 is only partially circular in design and onone side has an extension leading to the shaft 20.1. In the presentexemplary embodiment, this shaft 20.1 is designed more as a pipeline.

[0038] In the exemplary embodiment shown in FIG. 6, the filter housing2.1 is of removable configuration in that it is fitted in rails 33 whichare connected to the immersion housing 1. To remove it from the rails33, the filter housing 2.1 is pulled upward by the handle 4.2.

[0039] Furthermore, the filter housing 2.1 comprises a shell part 34 anda cover 35, the shell part 34 and cover 35 being connected to oneanother by means of a hinge 36. Folding open the cover 35 creates accessto an interior 37 of the filter housing 2.1, in which a pleated filter25.1 which has been folded up is inserted. This folded arrangementsignificantly increases the surface area of the filter 25.1.

[0040] In the shell part 34 there are holding means (not shown in moredetail) for the filter 25.1, which are configured in such a way thatthey provide the filter 25.1 with sufficient strength.

[0041] After it has flowed through the filter 25.1, the cleaned liquidemerges through the openings 24 and returns to the cleaning bath, asindicated by the arrow.

[0042] List of Reference Symbols 1 Immersion housing 2 Filter housing 3Housing 4 Handle 5 Cutout 6 Quick-acting nut 7 Quick-acting nut 8 Motor9 Electronics 10 Actuating button 11 Rod 12 Rotor 13 Rotor disk 14 Vane15 Partition 16 Ring 17 Space 18 Aperture 19 Outlet 20 Shaft 21 Window22 Antechamber 23 Partition 24 Opening 25 First filter 26 Cage 27Opening 28 Second filter 29 Collecting trough 30 Laminated stack 31Lamination 32 Aperture 33 Rails 34 Shell part 35 Cover 36 Hinge 37Interior R Device

1. A device for cleaning liquids, in particular edible oils, by means ofa filter (25, 25.1), characterized in that the filter (25, 25.1) isconnected downstream of a pump (8, 11, 12), the two together forming aunit which can be at least partly introduced into the liquid which is tobe cleaned.
 2. The device for cleaning liquids as claimed in claim 1,characterized in that there is a shaft (20, 20.1) for supplying theliquid positioned between pump (8, 11, 12) and filter (25, 25.1).
 3. Thedevice for cleaning liquids as claimed in claim 1 or 2, characterized inthat in a housing (3) there is a motor (8) for driving the pump (11,12).
 4. The device for cleaning liquids as claimed in claim 3,characterized in that the housing (3) is seated on an immersion housing(1) which includes a rotor (12).
 5. The device for cleaning liquids asclaimed in claim 4, characterized in that the immersion housing (1) isconnected to the housing (3) by means of quick-fit clamping elements(6).
 6. The device for cleaning liquids as claimed in claim 4 or 5,characterized in that the rotor (12) has a rotor disk (13), which isconnected to the motor (8) via a rod (11), and is fitted with vanes (14,14.1, 14.2).
 7. The device for cleaning liquids as claimed in claim 6,characterized in that there are apertures (18) in the rotor disk (13).8. The device for cleaning liquids as claimed in claim 6 or 7,characterized in that the rotor disk (13) is arranged beneath apartition (15) and in a ring (16).
 9. The device for cleaning liquids asclaimed in claim 4 or 5, characterized in that the rotor (12) rotates ina laminated stack (30), the laminations (31.1-31.3) having differentapertures (32.1-32.3).
 10. The device for cleaning liquids as claimed inclaim 9, characterized in that the apertures (32.1-32.3) increase insize in the direction of the shaft (20.1).
 11. The device for cleaningliquids as claimed in claim 8-10, characterized in that an outlet (19)leading to the shaft (20, 20.1) is provided in the partition (15). 12.The device for cleaning liquids as claimed in at least one of claims1-11, characterized in that the filter (25, 25.1) is positioned in afilter housing (2, 2.1).
 13. The device for cleaning liquids as claimedin claim 12, characterized in that the filter housing (2) is removablyassigned to the immersion housing (1).
 14. The device for cleaningliquids as claimed in claim 13, characterized in that the filter housing(2) is connected to the immersion housing (1) by means of quick-fitclamping elements (7).
 15. The device for cleaning liquids as claimed inclaim 13, characterized in that the filter housing is guided on rails(33) on the immersion housing (1).
 16. The device for cleaning liquidsas claimed in at least one of claims 1-15, characterized in that thefilter (25) is a metal filter.
 17. The device for cleaning liquids asclaimed in at least one of claims 1-16, characterized in that a secondfilter (28) is arranged downstream of the first filter (25).
 18. Thedevice for cleaning liquids as claimed in at least one of claims 1 to15, characterized in that the filter (25.1) consists of a pleatedtextile material.
 19. The device for cleaning liquids as claimed in atleast one of claims 16-18, characterized in that the filter(s) (25,25.1, 28) are positioned exchangeably in the filter housing (2, 2.1).20. The device for cleaning liquids as claimed in at least one of claims3 to 14, characterized in that a handle (4, 4.1, 4.2) for transportationor removal is provided on the housing (3) and/or on the filter housing(2.1).
 21. A method for cleaning liquids, characterized in that a pump(8, 11, 12) with a downstream filter (25, 25.1) is introduced into theliquid which is to be cleaned, and the pump is used to feed the liquidthrough the filter, so that the liquid returns to the liquid bathimmediately downstream of the filter.